To evaluate the efficacy of combination therapy with ranibizumab (RBZ) and panretinal photocoagulation (PRP) versus PRP alone in patients with treatment-naive bilateral proliferative diabetic retinopathy (PDR) as measured by mean change in visual acuity (VA), mean change in central retinal thickness (CRT) as measured by time-domain optic coherence tomography (TD-OCT) and incidence of vitreous hemorrhage (VH).